阅读理解

Directions: In this section there are reading passages followed by multiple-choice questions. Read the passages and then mark your answers on your answer sheet.

Passage three

As a volunteer, John Apollos is losing weight the old- fashioned way by eating less. Apollos has lowered his daily caloric intake 25% over the past eight months. The fat, not surprisingly, has melted away. But that’ s not the real reason Apollos and the other participants in the program are eating only three-quarters of what they used to. The researchers are trying to determine whether restricting food intake can slow the ageing process and extend our life span. “I feel better and lighter and healthier, ” says Apollos. “But if it could help you live longer, that would be pretty amazing. ”

The idea is counterintuitive: if we eat to live, how can starving ourselves add years to our lives? Yet decades of calorie-restriction studies involving organisms ranging from microscopic yeast to rats have shown just that. Last July a long-term study led by researchers at the University of Wisconsin, found that calorie restriction seemed to extend the lives of humanlike rhesus monkeys (恒 河猴) as well. The hungry primates fell victim to diabetes, heart and brain disease and cancer much less frequently than their well-fed counterparts did.

Scientists have suspected that calorie restriction could extend the life span of animals when they noticed that severely food-restricted lab rats lived twice as long as normal ones and were healthier.

One theory is that a state of slight hunger acts as mild but constant stressor that makes an organism stronger and more resistant to the ills of ageing. Taking in fewer calories also slows metabolism (新陈代谢) and some data indicate that humans with a slower metabolism live longer. If researchers could determine the mechanism, they might be able to mimic the effect of calorie restriction. That could be the ultimate benefit of the Calorie Study. “Calorie restriction is pretty much the only thing out there that will not just prevent disease but also extend maximal life span, ” says Dr. Marc Hellerstein, a nutritionist at the University of California. 

单选题 The purpose of the research that John Apollos participates in is to _____.
【正确答案】 C
【答案解析】第一段中间部分“The researchers are trying to determine whether restricting food intake can slow the ageing process and extend our life span. ” 提到实验的目的是看控制食物摄入是否能减慢衰老过程并且延年益寿， 即是否能延长寿命、 让人保持年轻， 故C项为正确答案。
单选题 What’ s the meaning of “counterintuitive” (Linel,Para. 2) ?
【正确答案】 A
【答案解析】该词所在原文位置中的后半句“if we eat to live, how can starving ourselves add years to our lives?” 的意思是：如果我们为了生存去进食， 怎么可能通过饥饿来延长寿命？ 可以从内容及语气上看出， 这样的结论是有悖直觉的，unconventional（非常规的） 最为贴切， 故A项为正确答案。
单选题 What does the research on rhesus monkeys imply?
【正确答案】 B
【答案解析】由关键词rhesus monkey定位到第二段末尾。 “The hungry primates fell victim to diabetes, heart and brain disease and cancer much less frequently than their well-fed counterparts did. ” 表明饥饿的比饱食的灵长类动物有更低的频率患糖尿病、 心脑病和癌症， 可以推断出限制卡路里的摄入可以让人类更少患病， 故B项为正确答案。
单选题 From Dr. Marc Hellerstein’ s words, we can infer that_____.
【正确答案】 B
【答案解析】由关键词Dr. Marc Hellerstein定位到文章末尾。“Calorie restriction is pretty much the only thing out there that will not just prevent disease but also extend maximal life span” 说到卡路里限制可能是唯一一个既可以预防疾病又可以延长寿命的事情， 可以看出有效的卡路里限制可以让人们生活得更健康、 更久， 故B项为正确答案。
单选题 Which of the following statements is NOT true?
【正确答案】 D
【答案解析】文章最后一段第二句说“. . . some data indicate that humans with a slower metabolism live longer. ” 代谢水平低的人活得更久， 据此排除A项； 从第二段恒河猴的实验可以看出well-fed的个体更易 患糖尿病、 心脑病和癌症， 据此排除B项； 文章倒数第二段提到“. . . severely food-restricted lab rats lived twice as long as normal ones and were healthier. ” 严格限制食物的被试老鼠 的寿命是正常的两倍， 并且更健康， 据此排除C项； D项不能从文章中得出， 故D项为正确答案。